<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <script src="./index.js"></script>
</head>
<body>
    <button id="count">点我</button>
    <div id="show"></div>

    <script>
      var a = (function () {
        var count = 0;
        var button = document.getElementById("count")
        button.onclick = function() {
          console.log(Event.listen);
          Event.trigger('add', count++);
        }
      })();

      var b = (function () {
        var count = 0;
        var div = document.getElementById('show');
        Event.listen('add', function(count) {
          console.log("接收到", count);
          div.innerHTML = count;
        })
      })();
    </script>
</body>
</html>